Looks good! A suggestion though: replace the bungies you're using to keep
things cat resistant with the neoprene kind. I've had sooo many of the same
kind of bungy core that you're using come flying out of the hook when the
retention ring gives out that I no longer use that kind. They don't seem to
give any warning. The neoprene ones seem to stay assembled a little bit
better IMHO.

BTW, the light fixtures you're using look really good. Are you using a
cover glass or are you running an open-top setup?